Regulating valve for rock drills



F. M. SLATER.

REGULATING VAL 0R ROCK DRILLS.

' APPLICATION JULY 6.1920- 1,414=,22. Patented Apr. 25, 1922.

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' ORNEY UNITED STATES" PATENT FRED M. SLATER, or EAs'romrENNsYLvANm, ASSIGNOR TO INGERSOLL-RAND COMPANY, or JERSEY CITY, NEW JERSEY, A CORPORATION or new JERSEY. V U

'REGU ATIN VALVE FORBJOOK nR-rLLs,

T 0 all whom it may concern Be it known that I, FRED M. SLATER, a citizen of the United States, residing at 'Easton, in the-county of Northampton, State of Pennsylvania, have invented a certain new and useful Improvement in Regulating Valves for Rock Drills, of which the following is a specification.

ance to'rotation' in drilling. Q

Another object of the invention isto enable a main valve to be automatically controlled by-means of an auxiliary pilot valve Which-is subject to a varying pressure within the intake side of the 'motor casingin accordance wlt-h the conditions of the work.

Further objects of the invention will here inafter appear and to all of these ends the invention consists of the devices and tea tures of construction substantially as hereinafter fully described and claimed in this specification and shown in the accompanying drawings in which, 7

Figure 1 is a top plan viewpartly in 1011- gitudinal section ot'so much of a rock drill as will illustrate the invention,

Figure 2 is a longitudinal'side elevation of the machine with certain parts in vertical section,- V a Figure 3 is an enlarged transverse sectional view of the rotating motor and automatic valve mechanism shown diagrammatically. Y

Referring tothe drawings the cylinder A of any suitable or usual form is provided with the usual front head B havingthe rotation sleeve C through which the drill steel D extends to receive the impact blow in this instance a gear motor being "shown within "the lback endportion "G of the ma Specification of Letters Patent. Patented Apr. 25, 31922. AppIication filed July s, 1920. Serial No. 394,227.

chine, comprising the gears H and J one of which as the gear J is keyed to a countershaft K at-one end," the other end of the shatt having a pinion 'L meshing with a gear 0 having a pinion P meshing with the gear'Q, on the rotation sleeve C.

The gears H andJ of the rotatlon motor are preferably provided with suitableroller bearings one of which is shown at R and the shaft'K has a-roller bearing 8 at its forward end. The shaft' Kpre'ferably passes through the chamberTln the walls ot'the' cylinder A which forms an exhaust chamber for the rotation motor. The chamber is vented to atmosphere through the openings U which muffles or silences jthe noise produced when air passes through motors of "The back end portion'Gof the drill'c'ylinder forming the motor casing is'closed bya suit-ableback head V havingthe motive fluid supply inlet TV, the water cap 'X and the automatic motor controlling valve mechanism. Motive fluid enters the machine at the inlet NV and passes to the bore Y ofthe cylinder A and also passes through the sup; V

ply port Z to the motor. The exhaust from,

the motor passes out through the exhaust portal to the exhaust chamherT and thence 5 to the atmosphere.

Within'the back an v.1; provided a main valve 6 having a pressure surface 'rep- 1 I resented by the front end 'cconstant-ly subjected to the pressure of the incoming motivefiuid tending to close the valve/ The end '0 is preferably somewhat smaller in diameter than the port '(Z so that the port cl is never fully closedbuta throttling effect is secured due to the tapered neck 6 of-Qthe valve,

The main valve 6 is'preferaloly provided with a tubularfbarrel f within which" a spring '9 is compressed tending"to open the valve, A rear pressure surface of the main valve, or rear pressure surfaces represented by the rear end of the valve.andithe'interior surfaces are subjected -to the varying pres sure du'egtov a relatively small amount of fluid constantly admitted trom' the intake of the li'nachine to 1 said {pressure surface or 7 surfaces and in this. instance such small amount of pressure is admitted through the. aperture :k in 'the end '0 of the main" valve;

The outward movement of the'irnai'n valve is rererabl ilimited bi means of'the t p An exhaust to atmosphere is provided from the rear pressure Surface or surfaces of the main valve through the exhaust aperture 7c and an auxiliary pilot valve 0 is provided for varying said exhaust. The pilot valve is preferably inthe form of ahollow cylinder closed at its inner end 79 and adapted to slide within a casing 7 open at both ends and held in position as by means of the cap r having the ports 8. The pilot valve 0 is at all times subjected to the pressure of the spring t forcing the valve in a direction adapted to produce the maximum exhaust opening from the rear pressure surface or surfaces of the main valve 7). In this instance the pilot valve 0 is provided with the apertures u in its walls arranged at an angle to the longitudinal axis of the valve so that as the pilot valve moves inwardly into the position indicated in Figure 3 for instance, motive fluid may exhaust from the space he hind the main'valve Z) through the exhaust port k, into the casing qthrough the port 4) and through the plurality of apertures u to the inside of the pilot valve and thence to atmosphere. V

The end 79 of the pilot valve is at all times subjected to the pressure in the motor through the port 10, tending to force the pilot valve in the opposite direction to reduce the communication between the rear pressure surface or surfaces of the main valve 6 and the atmosphere, because as the pilot valve 0 moves outwardly in the casing more or less of the apertures u are out off or closed.

In the operation of the apparatus, let it be assumed that the drill steel D for any cause, encounters increased resistance to rotation. A drag is thus put upon the'motor causing the same to run slower, which increases the pressure on the intake side within the motor casing G. The pilot valve 0 then moves outwardly, reducing the communication from the rear end of the main valve 6 to the at mosphere, which builds up the pressure hehind the rear end of the said main valve 6 and opens it further, still further increasing the pressure in the motor, and causing it to exert greater power for rotating thedrill steel. This condition continues until the drill steel works itself itree, in which case, the motor will momentarily race, and relieve itself of the pressure, dropping the pressure on the intake side in the motor casing, so that the pilot valve will then return to sub- 7 'stantially its original position and the main valve will return to normal position. This cycle of operations will be carried out whenever the conditions of the work require the automatic regulation. 7 V

I claim:

1. Ina fluid operated percussivetool, the

. combination of a fluid operated rotation motor, a valve casing having a supply passage leading to the motor, a valve adapted to automatically vary the opening through said passage inversely as the line pressure so as to maintain a substantially constant quantity of flow to the motor with varying line pressure, and adapted to automatically vary the said opening inversely with the speed of the motor so as to maintain approximately constant motor speed under varying loads, said valve being actuated in one direction by line pressure, and in the opposite directionv by spring pressure and line pressure reduced inversely as the speed of the motor.

2. In a fluid operated percussive tool, the combination of a fluid operated rotation inotor, a valve casing having a supply passage leading to the motor, a valve adapted to automatically vary the opening through said passage inversely as the line pressure so as to maintain a substantially constant quantity of flow to the motor with varying line pressure, and adapted to automaticallyvary the said opening inversely with the speed of the motor so as to maintain approximately constant motor speed under varying loads, said valve being actuated in one direction by line pressure, and in the opposite direction by spring pressure, and line pressure entering behind the valve through a restricted port and passing to atmosphere through a second restricted port. 7

8. In a fluid operated percussive tool, the combination of a fluidoperated rotationmotor, a valve casing having a supply passage leading to the motor, a valve adapted to an tomatically vary the opening through said passage inversely as the line pressure so as to maintain a substantially constant quantity of flow to the motor with varying line pressure, and adapted to automatically vary the said opening inversely with the speed of the motor so as to maintain approximately constant motor speed under varying loads, said valve being actuated in one direction by line pressure, and in the opposite direction by s 'n'ing pressure, and line pressure entering behind the valve through a. restricted port and pass ing to atmosphere through a second restricted port, and a pilot valve in said valve'cas' ing controlled by the motor pressure, governing the opening of said second restrictive port. a V

4-. In. a fluid operated percussive tool, the combination of a fluid operated rotation motor, a valve casing havinga supply pasproximately constant motor speed under varying loads, said valve being constantly 1 30 subjected'to spring'pressuretending to move the valve in a-direction to increase the opening through said passage, one pressure surfaceof said valve being constantly subjected to the pressureof the-incoming motive fluid tending to move the valve in the opposite direction to reduce the openingthrough said passage, another opposing pressure surface of the valve being subjected 'to'the varying pressure "due to a'relatively small amount of fluid constantlyadmitted through a restricted port from the intake of the machine behind said other pressure surface, means for exhausting the space behind said other opposing pressure surface of the valve through asecond restricted port to atmosphere, and a spring pressed auxiliary pilot valve in said valve casing automatically controlled'by the pressure inthe motor, governing the opening of said secondrestricted port. I

5. In a'fluid operated percussive tool, the combination of a fluid operated rotation motor, a valve casing having a supply pas sage leading to the motor, a valve adapted to automatically vary the opening through said passage inversely as the line pressure so as to maintain a substantially constant quantity of flow to the motor with varying line pressure, and adapted to automatically vary the said'opening inversely With the speed of the motor so as to maintain approximately constant motor speed under varying loads, said valve being constantly subjected to spring pressure tending to 1ncrease the opening through said passage, one pressure surface of said valve being constantly subjected to the pressure of the incoming motive fluid tending to move the valve in a direction to reduce the open ng through said passage, another opposing pressure surface of the valve being subjected to the varying pressure due to a relatively small amount of fluid constantly admitted from the intake of the machine behind said other pressure surface through a restricted port in the front end of the valve, means for exhausting the space behind said other opposing pressure surface of the valve through a second restricted port to the atmosphere, and a spring pressed auxiliary pilot valve in said valve casing automatr cally controlledby the pressure in the motor, governing the opening of said second'restricted port.

6. In a fluid operated percussive tool, the combination of a fluid operated rotation motor, a valve casing having a supply passage leading to the motor, a valve adapted to automatically vary the opening through said passage inversely as. the line pressure so as to maintain a substantially constant quantity of flow to the motor With varying line pressure, and adapted to automatically vary the saidopening inversely with the speed of the motor so as to maintain ap proximately constant motor speed undervarying loads, said valve being constantly subjected to spring pressure tending to move the valvefin a direction to increasethe opening through said passage, one pressure surface of said valve being constantly subjected 'tothe pressure of the incoming motive fluidtending .to move the valve in the opposite direction to reduce the opening through said passage, another opposing surface of the valve being subjected to the varying pressure due to a :relatively small amount of fluid constantly admitted tl'n'ough a restricted port from'thefintake ofthe mae chine behind said other I pressure surface, means for exhausting the space behindsaid other opposing pressure surface ;of the valve through a second restrictedportto atmosphere, and an auxiliary pilot valve governing the openingeof said second restrictedport. i v 1 1 V :5 7 In a fluid operated percussive tool, the combination of a fluid operated rotation motor, a valve casing having a supply passage leading to the motor, a valve adapted to'automatically vary the opening through said passage inversely as the line. pressure so as to maintain a substantially constant quantity of flow to the motor ith varying line pressure, and adapted to automatically vary. the said opening inversely With the speed of the motor so as to maintain approximately constant motor speed under varying loads, said valve being subjected to spring pressure tending to move the valve in a direction to increase the opening through said passage,

intake of the machine behind said other pressure surface, means for exhausting the space behind said other opposing pressure surface of the valve through a second restricted port to atmosphere, an auxiliary pilot valve in the valve casing governing the opening of said second restricted port, resilient means tendone pressure surface ofsaid valve being conanother ing to force said pilotvalve in a direction to I produce the maximiun exhaust opening through the said second restricted port to f the atmosphere, sald pilot valve also being at all times subjected to the pressure in the motor, tending to forcethe pilot'valve in-the opposite direction 7 to reduce the opening through said second restricted port to the atmosphere. I v i i 8 In a fluid operatedpercussivetool, the combinationof a fluid operated rotation mo- .tor, a valve casing having a supply passage leading to the motor, a valve adapted to automatically vary the opening through said passage inversely as the line pressure so as to maintain a substantially constant quantity of flow to the motor with varying line pressure, and adapted to automatically vary the 1 said opening inversely With the speed of the motor so as to malntain approximately constant motor speed under varying loads, said valve being constantly subjected to spring pressure tending to move the valve in a direction to increase the opening through said passage, a front pressure surface of said valve being constantly subjected to the pressure of the incoming motive fluid tending to move the valve in the opposite direction to reduce the opening through said passage, a rear pressure surface of the valve being subjected to the varying pressure due to a rel atively small amount of fluid constantly admitted through a restricted port from the intake of the machine to said rear pressure surface, the valve also being provided with second restricted port from the rear pressure surface of the first named valve to the atmosphere, the opposite end of said pilot valve being at all times subjected to the pressure in the motor, tending to force the pilot valve in a direction to reduce the opening 7 through said second restricted port from the rear pressure surface of the first namedvalve to the atmosphere.

In testimony whereof I have signed this specification. V

FRED M; SLATER. 

